As described in patent application Ser. No. 08/818,136 filed Mar. 14, 1997, a frame system for providing reusable framing structures for settable materials such as concrete includes apertured panels which, when erected, form the mold surfaces for such settable materials as concrete. The utilization of these apertured panels and oversized plugs results in a self-aligning framing structure that permits the rapid erection of walls, floors and the like in which the panels and thus the walls are automatically trued. In one embodiment, the apertures in the panels are formed in a rectilinear array with the apertures equidistant one from the other.
As discussed in the aforementioned patent application, the panels are of a honeycomb structure in which there are two face sheets to either side of a honeycomb structure.
While these panels are suitable for use in the buttressed framing structure described in the above-mentioned patent application, they are somewhat heavy due to the number of sheets used to form the panel as well as the honeycomb structure itself.
It is important to note, that the panels themselves carry considerable loads when concrete is poured in between facing panels.
In the honeycomb environment, the structural rigidity derives from the coaction of the honeycomb structure with the front face and the back face of the panel, such that the panel itself resists bowing outwardly when the heavy concrete is poured into the mold formed by these panels.
There is therefore a need for providing a plastic apertured panel which can be of lighter weight, yet obtain the same or greater rigidity so as to resist the concrete pour during the pouring operation as well as providing rectilinear rigidity during the initial framing process.
By way of further background, and in order to describe the necessity for a reusable panel framing system for use in construction, in the past, it has been common to pour concrete into forming structures or molds made of wood or metal which are fastened together with nails or bolts on the job site. As early as the Pharoahs time, wooden panels have been oriented in a vertical direction, with settable material being poured in from the top and with panels being fixed together with nails or other such devices. In the present day, buildings are constructed by methods of utilizing panels made of either wood or metal to contain the concrete until the concrete sets. In general, these panels and the structures that hold them in place during the setting period have either been retained within the building or removed after the concrete or other settable material has set up.
The problem with forming settable walls and columns in this manner is that measurements must be taken each time the forming structures are fabricated on site, meaning that all of the edges and panels must be trued and vertical so that the walls or other structural members which result from the pouring of the concrete likewise come out with parallel sides and right-angled corners. In order to provide for the rectilinearity of the walls, skilled artisans must make complicated and precise measurements to assure proper placement and sizing of the resulting structural members. This oftentimes requires utilization of laser datum lines to make sure that the forming structures are appropriately oriented. Therefore, the utilization of traditional molds for settable concrete requires a highly skilled artisan. The skill relates both to experience in providing the required forming structures and also in minimizing the time necessary to construct these structures.
For instance, it takes a skilled artisan a relatively large amount of time to provide a suitable mold for construction of a wall and column combination. In addition, oftentimes it is the case that the frames and panels utilized in the fabrication of the mold out weigh the weight of the concrete to be poured. This requires the utilization of a large amount of man power and heavy machinery resulting in longer construction times. Furthermore, since the mold walls or panels and buttressing equipment are massive, precision molding is relatively difficult, which again warrants the utilization of experienced artisans.
For instance, when building columns or walls are to be erected, it sometimes takes a skilled artisan as much as five or six hours to provide a suitable mold for a wall and column combination. Another factor in the fabrication of molds for settable concrete is the shear weight or mass of the elements required to make up the mold. Oftentimes it is the case that the frame and panels utilized in the fabrication of the mold out-weigh all the concrete to be poured. For instance, the machinery necessary to buttress a wall on both sides to a distance of 10 feet high can be as much as 2-3 tons, whereas the wall itself, once having been fabricated, is less than 500 pounds.
Since the mold walls or panels and buttressing machinery are massive, precision molding is relatively difficult. It will be appreciated that high precision is required most notably in high-rise type of buildings, those buildings exceeding 20 stories. The precision is required because as one builds up from a base, any mistakes in the position of the wall at the base level affects higher stories of the building. As will be appreciated, it is very difficult to correct for mistakes made at a lower level when building walls at a higher level.
It will also be appreciated that when building molds for retaining concrete, removing nails and screws or bolts in order to effectuate a modification of the structure due to change of plans or other factors is virtually impossible. This is because in general the panels which are buttressed are not capable of being adjusted on the fly to accommodate changes of plan.
While in the past metal panels have been preformed to various panel sizes, the utilization of these panels is difficult in situations where modifications must be made on the spot to accommodate architectural changes or, in fact, to accommodate unforeseen circumstances during the construction of the building. When these panels are replaced with panels of different sizes or configurations, it is not always possible to have them aligned and placed appropriately.
It will be appreciated that the difficulty in aligning these panels stems from both the weight and the inability to dimension them properly. The reason for the requirement of a skilled artisan at this point is that the artisan must take dimensions over a number of diagonals and to calculate out the appropriate dimensions for the panel or the buttressing structure. Mistakes are often made in the on-site calculations, resulting in a formed wall that does not come out to specification. The result of a wall not meeting the specs is costly. Therefore, utilization of highly paid artisans is required to make sure that such an occurrence does not happen.
As described in the aforementioned patent application, rather than requiring a skilled artisan on-site to make the measurements for the panels and the buttressing structure, in order to provide the appropriate molds for the poured concrete or other settable material, in the subject invention, all of the framing members and panels are apertured in such a way that when dowels are used to join the members together, all of the panels and walls are automatically trued. In one embodiment, the apertures in each of the panels or framing members are in a rectilinear array, with the apertures equidistant one from the other. This means that alterations can be made on the spot, in the size or dimension of any building component, without having to remeasure the entire job.
In one embodiment, the apertured panels and framing members are prestressed by the presence of an array of removable and interchangable oversized plastic plugs in the apertures. When an oversized plug is inserted into an aperture, the plug deforms inwardly when in place, thus providing prestressing in that structural element.
Moreover, when members are joined together by connecting apparatus from oversized plugs in adjacent members, the members are accurately positioned due to the accuracies associated with the holes into which the oversized plugs are inserted. Thus, not only do the apertures or holes in the apertured members provide for initial truing, this truing is maintained due to the fact that the entire structure, when assembled, is stable and rigid.
In one embodiment, the members are made of light weight material, such as a composite plastic material made of different layers, with a honeycomb structure being preferable and with the honeycomb sandwiched between two exterior sheets. The sheet which is on the pour side of the panel can be patterned by merely providing the sheet with the appropriate pattern or design.
In operation, apertured base strips are laid out in a rectilinear fashion and screwed down into the foundation floor. This positions the apertures in each one of these base strips, such that when members are attached to these base strips through the utilization of the plastic dowels, the rectilinearity or dimensional stability of the resulting structure is maintained.
In one embodiment, apertured horizontal and vertical channels are laid and erected, respectively, on the top of the apertured base strip by the means of plastic dowels. The combination of these channels with base strips and dowels supports and positions the panels forming the walls of the pour and holds them in place both horizontally and vertically.
It will be appreciated that the apertured panels constitute the main component of the subject system. Note, these panels made of composite plastic materials are prestressed by the presence of an array of removable and interchangable oversized plastic plugs. These oversized plugs, in one embodiment, have an outwardly elliptical surface, such that when these plugs are forced into a member by pneumatic means, the plug shrinks imperceptibly as it goes through the hole. This being the case, the pressure between the outer surface of the plug and inner surface of each of the holes is increased such that the friction fit provides prestressing. Thus the utilization of the oversized plugs provides a structure which is rigid and dimensionally exact.
In one embodiment, the oversized plugs are removable, again by pneumatic means. Moreover, in one embodiment, the exterior surface of the plugs has a retaining sphere or bulb which snaps into place in the apertured members to maintain the plug in place. Note, the aperture into which the plug is placed is provided with mating cup-shaped holes into which the detents fit so as to determine the location of the plug within the aperture.
It will be appreciated that this is an all plastic system in which the plugs themselves are made of plastic. In order for the plug to be easily insertable and positioned within the apertures of the frames, it is important that portions of the plug engaging the walls of the aperture be flexible while other portions of the plug be rigid.
In one embodiment, the plug is provided with a central bore to permit devices to be secured to the plug and also to permit removal of the plug, such that the plug can be grabbed and pulled from the aperture. The bore is also utilized to accommodate interlocking plugs such that the various apertured members can be locked together at the plug. Alternatively, the plugs can be used by themselves simply as an anchoring device for mating structural elements.
In another embodiment of the plug, a circumferential annulus is provided in the bore such that when it is time to remove the plug, a gun-carried device is utilized to penetrate the bore of the plug and to pull out the plug by coaction with the annulus in the wall of the bore. In order to accomplish this, the bores are given a square or rectangular cross-section, such that a tool can be inserted around a round bolt passing through the square bore so that it can grab the plug at the aforementioned annulus while still being insertable to either side of the round bolt.
In another embodiment, the vertical channels for the wall panels are hingable, with the angle of the walls being set by inwardly projecting overlapping apertured tabs or base strips, with the angle being set by the overlying holes and the dowels therethrough. Thus the walls can be oriented at any desired angle.
In a further embodiment, removable conduits for the placement of wires, pipes and the like can be attached to the panels at the plugged apertures, whereas in another embodiment, apertured composite plastic frames are provided to brace the panels either from a floor base strip or from a ceiling frame, which also like the panels, are prestressed by the plugs and are made of composite plastic material.
In summary, a universal reusable system is provided for molding concrete or other settable fluids for use in building construction. In the subject system, apertured composite plastic panels and frames, prestressed by the presence of an array of removable and interchangeable oversized plastic plugs, are positioned and held in place by a framing system which utilizes a combination of apertured strips used as base guides and both vertical and horizontal channels, as well as dowels and plugs. The use of apertured panels and framing system provides for a reusable assembly whose dimensions can be readily set on site for each application and whose rectilinearity is maintained either by the dowel-aperture combination or by a combination of oversized plugs in adjacent members to be joined and connectors therebetween.
While the reusable nature of the plastic frame and panel structure permits economic fabrication of concrete walls, and at the same time assuring that the walls are true due to the overlapping of mating holes in the overlapping apertured members and the use of plastic dowels through the overlapping holes, lighter weight strong panels are required.